Dr Kieron Rooney: How Can We Maximise Fat Burning During Exercise?

Watch the full interview below or listen to the full episode on your iPhone HERE.

Guy: This week welcome to the show Dr. Kieron Rooney. He is a researcher in Metabolic Biochemistry from University of Sydney. Kieron’s research portfolio has included both human and small animal studies investigating the role of diet and physical activity on parameters of fuel storage and utilisation as they pertain to dysregulated metabolic states such as obesity and type 2 diabetes.

Kieron is a fun, down to earth guy who gives us an incite to what is going in the world of nutritional study from an academic perspective. So if you are wondering why there could be so much disagreement out there on the world of nutrition, then watch this as Kieron sheds some light on what’s really going on!Use Snapchat? Follow me at: GuyL180 or Click Here.

Audio Version

Questions we ask in this episode:

What is “Fat max” and how do we measure it?

Where does exercise intensity fit into it?

How do we become part of your research study?

How do we maximise post-recovery dependant upon our goals?

If you were a young elite athlete, which dietary fuel approach would you take?

180 – Fuelled By Nature

HOW WE EAT AND EXERCISE – PARTICIPANTS NEEDED!

We need participants from across Sydney to undertake an exercise test and answer some questions about what they eat, to determine how habitual diet effects how we burn energy during exercise.

Other testing includes; blood and urine tests, genetic testing, anthropometry analysis and dietary questionnaires.
To participate, you must have had a relatively consistent diet and maintained a stable weight (+/-3% in the preceding six months).CLICK HERE for more info.

Full Transcript

Guy
[00:00:30] Hey everybody. Welcome to another fantastic episode of the health sessions, and of course, I’m Guy Lawrence of 180 Nutrition. Today, we’re cutting through the confusion and connecting with a seriously global health and wellness leader and his name is Dr. Kieron Rooney. We welcome him back to the show today to discuss another fantastic topic which is fat adaption and oxidization because Kieron has actually been putting a study together and he’s actively doing it at the moment, which in a nutshell, he’s going to be wanting to know how we can best utilize fat to be burnt through exercise.
[00:01:00] We were very happy to get Kieron on today. We’ll get into all sorts of topics including recovery, exercise intensity, where does fat adaptation sit within all of it including low carb, building muscle mass. It’s all in there and it was a fascinating journey. Now, Kieron has a wealth of knowledge and I would definitely say you probably need to listen to this podcast a couple of times to truly grasp some of the concept Kieron is talking about. If you do get it, it will play a big role in the way you actually think about your training, your timing and the foods you eat as well moving forward, which is fantastic.
[00:01:30] Now, Kieron as well is actively looking for volunteers in Sydney as we speak. If you do volunteer your time, you’re going to require about three hours and from it, you’re going to get a free health assessment and they’re going to do some fitness test on you as well and even take some blood markets so then they can use this as part of a big study Kieron is doing in terms of how well you’re actually utilizing fat in the body as fuel while exercising.
[00:02:00] If you are keen to do that, you can drop Kieron an email, so it’s kieron.rooney@sydneyedu.au. That’s kieron.rooney@sydneyedu.au. What you can do is well, just do a Google search for him. You can come back to our website, type in Kieron, this will come up. All the information is going to be there for you so if that’s something you’re interested in, I highly recommend you check it out. I’m going to participate in January myself. Without further ado, let’s get onto the show. Enjoy. Hi. This is Guy Lawrence. I’m joined with Stu as always. Hey Stu. Good morning.Stu
Hello mate. Good morning.Guy
[00:02:30] Our fantastic guest today who we welcome back to the show is Dr. Kieron Rooney. Kieron, welcome back mate.Dr. Kieron
Good morning. Thanks Guy, thanks Stu. Glad to be here.Guy
Oh man, looking forward to it. The last episode became very, very popular and looking forward to the pearls of wisdom you’re going to share with us today for us and our listeners as well. Just to kick-start the show buddy and the fact that some people might not have listened to the last show, so we’re keeping it to our shoulder, but if someone stopped you in the middle of the street and said, “What do you do for a living mate?” what would you say?Dr. Kieron
I guess I should start with what I get paid to do which is I’m an academic at the University of Sydney and there, I am a course director for the Bachelor of Exercise, Physiology degree. I do research into sugar metabolism. At the moment, we’re looking at sugar withdrawal. That’s our aim for the next three years but also sugar regulation from a public health perspective as well.Guy
Perfect, and I’d throw in guest speaker also-Dr. Kieron
Yeah. Look, always happy to chat to people, so more often than not, if I get invited to give a talk, I’ll probably say yes. For that, I’m mostly talking about some of the biochemistry, exercise, physiology work I do which is regulating fuel metabolism or it will be around about the health detriments of sugar and how we may or may not try to improve that.Guy
[00:04:00] All right, brilliant. Look, as well mate, during this conversation today, we might have to pull you up a few times if you get too technical on us.Dr. Kieron
Sure. Not a problem.Guy
[00:04:30] I say that in advance. Look mate, we’ve been excited to get you back on the show. We caught up for a conversation last week and you’ve been talking about this grant and this study that you’re about to basically kick-start very shortly. If not, it’s underway already. Let’s start there. Can you tell us about what it’s about, like even of what you’ve learned so far on why is this study do exciting moving forward for everyone thus listening.Dr. Kieron
[00:05:00] Sure, so that’s right. The last time we spoke, at that point, we’d just been writing up the grant. We’d written up the ethics proposal to say what it is that we wanted to do. Since then, we’ve actually gotten ethics approval, we’ve gotten some extra funding for it and we’re actually recruiting. We’re looking for 112 to 120 people and we’ve got 50 already. Effectively, what we’re looking at is we’re investigating this phenomenon called maximal fat utilization or fat max, people might call it or maximal fat oxidation.
What we’re really trying to pick apart is whether or not what you habitually eat impacts the maximal rate of fat oxidation. We’re looking-Guy
[00:05:30] Questions straight off the bat, sorry mate. When you say fat oxidization, just to get a clear picture in people’s minds, is that the fat that we’re eating within dietary or is that the fat that our bodies hold in or is that a combination of both as fat for fuel?Dr. Kieron
[00:06:00] It’s fat for fuel. It’s most likely when we’re measuring it, we’re measuring the fat that’s already been stored on your body. How we measure this, when we think about it, typically, when you exercise, people accept that you’re burning predominantly two fuels. You’re burning carbohydrates or you’re burning fat to meet the energy demand of that exercise. You will be burning a bit of protein but it’s really difficult for us to measure that by the way that we do it, and I’ll explain what I mean by that.
If you think about air, air is predominantly three gases. It’s roughly 80% nitrogen, 20% oxygen and a little bit of carbon dioxide in there as well. What we’ll do for individuals is we can measure the amount of air that you’re blowing out during exercise. Now, we know nitrogen is an inert gas for us, so we don’t metabolize it so that should stay constant.
[00:06:30] We can track the change and the amount of oxygen and carbon dioxide that’s in the air that you’re breathing out. Now, 50, 60 odd years ago, people have done calculations that might lead to assumptions that depending upon how much oxygen and carbon dioxide is appearing or disappearing in your [respiratory 00:06:47] gases, we can measure whether or not that’s you burning carbs or if it’s you burning fat.
[00:07:00] For example, most people will be aware of something called the respiratory quotient or your RQ, which is your ratio of carbon dioxide in your breath compared to oxygen. We typically say yeah, the closer that is to one, then you’re more likely burning carbs and the closer it is to say .7 which is pretty much the larger you get to, you’re most likely burning fat. We take it to another level. We take it to the next level on that.
[00:07:30] We can take those absolute numbers of oxygen and carbon dioxide, feed them through some calculations and that will tell us an absolute amount of carbohydrates or fat that you’re burning in grams per minute, and that’s what we’re looking for. What we do in our exercise test is we’ll get people into the lab, we’ll put them on the bike and we’ll get you working at a really low intensity.
[00:08:00] We put you on the bike at about 35 watts, and we hook you up to a machine that’s measuring the oxygen, carbon dioxide, nitrogen that’s coming out of your breath. We then, every three minutes, increase that intensity by another 35 watts. You’ll start at 35 then you’ll go to 70 then you’ll go 105 and so on until you hit maximum power output. Meanwhile, every three minutes just before we put the intensity up, we’re measuring the gas analysis there.
An estimate was how much of the energy demand you’re putting out is being met by carbohydrate or fat.Guy
It’s the fat max.Dr. Kieron
Yeah, so where fat max comes into it is whenever you do these calculations, you notice two specific patterns. Carbohydrates, at rest, you’re burning relatively little amounts. It might be .3, half a gram per minute and then as you increase intensity, it increases and increases until you hit a threshold where it massively increases. You might get up to one, two, three, grams per minute that you’re burning.
[00:09:00] Fat’s different though. With fat oxidation, what you’ll see is you’re burning a small amount, might be .2, .3 grams per minute. Then as we increase intensity, the amount of fat that you burn starts to increase. You might get up to .5, .6 grams per minute, but then you hit a threshold where it starts declining again. What you can find is that as you increase somebody’s intensity, the amount of absolute fat that they’re burning is actually declining.
That point that you have hit before it’s starts to decline is what we call your maximal fat oxidation rate.Stu
That’s interesting. If I was listening to this and thought, “Right, I’m … I want some of that. I’ve got loads of fat to burn,” how can we stop that decline? Why does that decline stop? Why doesn’t it just keep trending upwards?Dr. Kieron
[00:10:00] That is something that has been a investigation at least for 50, 60 odd years. In the very early days, the Randle Cycle was a series of experiments which suggested that there were byproducts from when you burn carbohydrates that specifically inhibit your capacity to burn fat. As you start increasing your carbohydrate reliance, there’s things there that specifically inhibit the amount of fat that you can burn.
[00:10:30] It might also be muscle acidosis. As you increase the acidic state of your muscle, there are proteins and fat oxidation that don’t work as well as they were before. Really, at the moment, we don’t have a clear cut message as to what it is that’s specifically inhibiting that. What we’re particularly interested in our study is what is the maximum threshold you can get to or the absolute amount that you can get? This is where some of our current thinking has been somewhat deficient over the history of some of our research.
[00:11:00] I want to say ours. I’m doing a royal we there. I’m embracing all exercise physiologists for the last 100 years or so, not specifically saying my group being deficient. What I mean by that is we can have a look at a couple of selective studies. There was a paper from 2005 of Edibles Group. They looked at 300 general population participants, had them come in and do these maximal fat oxidation tests.
[00:11:30] Now, when they look at those 300 odd individuals, the average fat max that somebody is burning is around about .46 grams per minute. The range can be anywhere between .2 to one gram per minute. Just this year, we had a study which by Randle, not the original Randle from 50 odd years ago, but another group, who looked at a whole series of elite level athletes who have been coming in through the Gatorade Sports Science Institute over the last couple of years.
[00:12:00] Now, in those studies, That was over 1,000 athletes that they had in there, the average maximal fat oxidation was .7 grams per minute. Again though, there’s this range of somewhere between .2 grams up to 1.3 grams per minute. We know that there’s a lot of individual variants for how much fat somebody could access during their exercise capacity. Now, where this became particularly interesting from our perspective was when we have a look at a paper that came out from Jeff Volek earlier in the year late last year where he took really highly trained athletes and … So highly trained triathletes.
[00:13:00] They’re VO2 max levels are in the 60s, so they’re amongst the top high numbers that you could see, and they had two different groups, one group that were habitual carbohydrate eaters and another group who were self-identified, low carbohydrate ketosis athletes. Now, the regular carbohydrate eaters, they showed a fat max level again of around about that .7 grams on average, a range being between .4 and one gram in line with what we had previously seen over the last 10 years in general population and other athletic populations.
[00:13:30] The handful of low-carb, ketosis athletes they had, they’re average was one and a half grams per minute and their range was 1.2 up to 1.8. In that group of athletes, the lowest amount of maximal fat oxidation recorded was higher than the average amount for every other population that we’d seen up until that day.Stu
Do you think that that’s specifically because of their diet or because they were training at such an elite level that they’re doing so much more?Dr. Kieron
[00:14:00] This is one of the challenges that we’ve got. Amazingly, over the course of research into maximal fat oxidation, habitual diet has been really somewhat neglected. We know lots about limitations for maximal fat oxidation. We know that there’s a sex difference, not whether or not you’ve had any recently but whether you’re male or female. We know that there’s a difference from training so if you take a group of individuals who don’t train often, they’ll hit their fat max early, around about 30%, 40% of their VO2 max.
[00:14:30] They weren’t as high as somebody who trains regularly. Someone who trains regularly, they might hit their fat max at 60% or 70% of their VO2 max, and they’ll also hit higher numbers. We know that it will be different depending upon whether you’ve done your exercise fasted or whether you’ve been fed. What we haven’t really had is any good comprehensive study that corrects for sex, corrects for fed state and corrects for training status but then also uses habitual diet as a confounder, and that’s where our [crosstalk 00:14:50]-Guy
[00:15:00] Question I’ve got for you then Kieron is once you’ve done this study and you’ve got all this data back, what are you going to do with it and then how would that apply to people moving forward?Dr. Kieron
[00:15:30] What we’re trying to do is we’re looking for … We’ve got a budget to do 120 people. What we’re trying to get within that 120 people is a really widespread of habitual diet intake. Our primary focus is to try and find people who have varying degrees of carbohydrate intake. We focus on carbohydrates because we think it’s as strong a driver for accessing stored fuel than may be dietary fat or dietary protein.
[00:16:00] That’s just one of the assumptions we’re making, so effectively, we’ve got low-carb, Dan Andrea, helping us recruit. We’re looking for anybody who might be very low carbohydrate, high fat individuals. We’re trying to get standard Australian diet individuals who, if the Australian Bureau of Statistics data holds true, they’re getting 250, 300 grams of carbohydrate a day, half their energy coming from carbs.
[00:16:30] We’re also looking for maybe there might be some people out there who subscribe to the Ornish diet where it’s 80% of your energy from carbohydrates. What we’ll do is we’ll get individuals into the lab. We’ll take a suite of health markers, so we take bloods to measure your blood lipids, measure some cardiovascular disease risk factors. We measure your body composition, we then put you on the bike, so where we’ll measure your VO2 max.
We’ll measure your fat max, we’ll measure your lap take threshold but we’ll also do three different diet histories on you to try and really characterize you by dietary type. We’re looking for anybody who can come in and what we’ll do at the end is we’ll do all the conventional analysis. We’ll have a look at maximal fat oxidation, we’ll group by sex, we’ll group by age, we’ll group by training status.
[00:17:30] Then what we’ll also try and do is match people for those major drivers who only differ on carbohydrate content. What we’re looking to see there is whether or not, in a general population group, we can see this increase or effect on maximal fat oxidation that’s already been shown in a very tightly controlled, elite athlete group. Because the interesting thing then would be if we can identify whether or not our habitual diet is impacting the gains you can get from fuel utilization during your everyday activity.

[00:18:00] Typically, people will tell us that maximal fat oxidation is only driven by the amount of intensity that you do and your level of fitness, and maybe to some extent, your age. Now, we know that there’s a lot of discussion at the moment in general population that exercise is no good for weight loss. It might be good for weight maintenance, but the capacity for it to really impact your energy balance is minimal. That’s most likely driven by the fact that when we think about how much energy we’re taking in, it gets swabbed.
[00:18:30] What if everything we know about fat oxidation during exercise and the maximal amount we can access it has simply been limited because we’ve got inappropriate, habitual diet knowledge? In this instance, we might be able to say, “Well, by limiting your carbohydrates or by looking at how you might time it appropriately, you can actually increase your capacity for fat burning during exercise.”
[00:19:00] Now, why this is important, we still really don’t know. Now, one thing we need to keep in mind is for the most part, the conventional wisdom at the moment is the amount of fat you burn during an exercise session has very little, if anything, to do with your weight maintenance. There’s a good reason for that. If your maximal rate of fat oxidation is half a gram per minute and you do even an hour’s worth of exercise at your max fat oxidation rate, you’re burning 30 grams of fat.
[00:19:30] Right now, 30 grams is not going to impact is not going to impact your scale measurement at all. What could be really important here is some of the other associations that we have. There’s evidence out there to suggest that people who have the highest peak rates of fat oxidation during exercise also have the lowest accumulation of cardiovascular disease risk factors. If we’re not just thinking about weight loss but we think about health generally and the role that exercise can play in that, it might be that you’ve got greater health gains by being able to tap into this extra resource of fat during your exercise, and that [crosstalk 00:19:42].Guy
Just to be clear for all the listeners, at the time of recording right now Kieron, you’re still looking for 70 people to participate.Dr. Kieron
That’s right.Guy
Which is going to be almost like a free health assessment, right, if you take care of-Dr. Kieron
[00:20:30] Absolutely. We’ve got ethics to recruit males between the age of 18 and 54 and females between the age of 18 and 64. We’ll do a health screen on you over the phone to make sure you’re able to do our max test. Then you’d come in and there’s no cost to you. All you’ve got to do is find a way to get to Lidcombe which seems to be difficult for some people. What you’ll do is a around about a two, two and a half hour visit. We’ll have assessed your body composition, we’ll give you your waist-hip ratio.
We’ll take bloods that we send off to a pathology lab to do a full lipid profile on you. We’ll often do your glucose and insulin so you can get a good score of your insulin sensitivity. We’re doing HbA1c which is a good indicator of your long term glycemic control, and then we’ll give you your VO2 max and we’ll also be able to tell you your power output that you can exercise at which is maximal fat oxidation rate.
[00:21:30] We’ve got 50 down. We’re looking for 60 to 70 more people, and really what is another secondary outcome that we’re looking for, while we’re looking for different dietary types is whilst we’re primarily focusing on macro-nutrient content, we’re also hoping to get a good enough dataset to look at diet quality. If the data set fits, what we’d like to be able to do is ultimately match people for fitness, for sex and for carbohydrate intake, but then also put in carbohydrate source as a confounder.
[00:22:00] For instance then, is there a difference? Can we take someone who might be getting 40% of their carb intake but one person’s getting it from highly refined starches and sugars versus somebody who’s getting it from vegetables and whole grain, for example, and does that have an impact on the health markers as well. That’s we need a good 120. We’re trying to advertise as widely as we can because if we can get as many different dietary types for people who identify by diet type, then we might be able to do that across [crosstalk 00:22:08].Guy
Brilliant, and where’s the best for contact to inquire more mate? I’ll-Dr. Kieron
[00:22:30] If you guys can tweet around the flyer, that would be great. That’s got my email address on it. It also has the email address for the research student who’s doing this as part of their thesis. Ultimately, if you just Google Kieron Rooney, University of Sydney, you’ll find my staff profile and there will be a link for an email there. Just email me. I can send you a full participant information sheet and that will give you all the details that you need to be able to come in.
The idea is we hopefully will … We’ll keep testing from now up until the 14th of December and then the uni shuts down for the Christmas period, and then we’ll be retesting again from around about the middle of January until we get our 120 participants.Guy
Perfect.Stu
Got it, and so from a participant perspective, is it just a single visit or do I need to make multiple visits?Dr. Kieron
No. It’s absolutely just the one single visit for this test. Some people might suggest that for an accurate maximal assessment, you should get people come in for two or three assessments. We know that that will impact our recruitment but also, our budget doest account for that.Stu
Got it.Dr. Kieron
If we wanted to do that method, we’d have to have enough money to test 360 people but we don’t have that at the moment so hopefully-Stu
Dr. Kieron: Yeah, but the idea would be that this 120 people will give us one, a really nice dataset that we can get published but two, also gives us a platform as a proof of concept so we can apply for more funding and do a more comprehensive study down the trail.Stu
Got it.Guy
[00:24:00] Brilliant. I’ve got a question for you Kieron and it’s in the same context because this has come up quite often with me, especially when I talk to people I train on a regular basis from CrossFitters to triathletes and so forth, and that is … With fat adaptation as fuel and the intensity of the sport that they’re doing. Because some have very short, sharp bursts.
[00:24:30] You look at the CrossFitters at the CrossFit games and things like that to even the shorter triathlons and things like that, then to your long endurance competitors, that seems to be where all this study started from from what I understand, was Steven Phinney and Jeff Volek. Where does that come into it with fat adaptation and the intensity of the sport? Should it be across the board or you need to look at them completely differently?Dr. Kieron
[00:25:00] Yeah. Look, it’s a great question because it’s something that needs to be teased apart a little bit more. I mean when we think about fat oxidation and intensity, there are a couple of things we need to keep in mind. The first one is the maximal rate that we should burn fat will most often or not occur at around about 40% to 60% of your VO2 max depending upon on how trained you are.
[00:25:30] Very few people have shown that the maximal fat oxidation occurs after that. You’re talking about someone doing some moderate intensity exercise work there, but to be fair, those tests are always done as one continuous bout. You get on the bike and we start increasing intensity every three minutes or it might be every seven minutes, or it might even be every one minute depending upon what protocol you subscribe to.
[00:26:00] How well people have looked at if it didn’t work there for measuring fat oxi … Yeah, that date is not really there. What we do know is where that fat oxidation occurs can fluctuate left to right. It can occur at lower intensity if you’re not as well trained and it will shift to the right so you can do more work, you can burn more fat at a higher intensity as you train. What’s really interesting for your question there, Guy, is this paper that came out earlier this year with Randle.
[00:26:30] I pulled it, so I can tell you right. It’s Rebecca Randle and it was in medicine and science and sports and exercise. Now, for anybody watching, if table [inaudible 00:26:22] that you want to have a look at … Table four you want to have a look at. Because what they did there was with their 1,100 athlete, they broke down their data by sport group. Now, so they had 280 odd soccer players, 160 basketballers, 140 tennis players, some baseballers, American footballers, a couple of rugby players.
[00:27:00] When they break down their data that way, it’s fascinating to have a look at their maximal fat oxidation. They are all around a very similar level, so soccer players, on average, .58 grams per minute. Tennis players, .51, American footballers, .65, golfers, .49 but if you had a look at this data, it would suggest to you that it doesn’t really matter what sport type you are. You are capping your maximal fat oxidation at a very similar level.
[00:27:30] Where this is of particular interest is they haven’t controlled or looked at habitual diet. It could be that it would be the generation populations, and we know that a very strong carbohydrate intake drive for elite level athletes. There’s a good chance these guys are eating 200, 250, 300 grams of carb a day, and it’s mostly likely that’s what’s capping their fat oxidation. It could be that there is an effect of different sports but it’s being swamped by their dietary intake data.Guy
There’s so many variables. It makes your head [crosstalk 00:27:51].Dr. Kieron
That’s right.Stu
Let’s just say that you had a son, so Kieron junior, “So dad, I want to be an elite athlete, tell me how I should eat? Because you’re … You’re a smart dude. What are you going to cook, what are you going to cook for me?”Dr. Kieron
[00:28:30] Look, I do have a nine year old and he is particularly lean and he does go to a little athletics, so look, I might be tapping into a little bit of n equals 1 experimental data here. Look, I don’t carb-restrict him. I think one of the things we need to pick apart with dietary intake, particularly with carbohydrates is that age specificity. As much as I am a proponent for carbohydrate restriction and lower carbohydrate diets, I think that’s really relevant for people like us.
[00:29:00] I turned 42 weeks ago. My cells aren’t doing anything but just keeping me alive for a couple … A few more years. That’s it. I’m not growing anymore. I’m trying to hold off age-related atrophy as long as I can, and so my requirement for metabolic need, especially for carbohydrates might not be that great. What we really use carbohydrates for is they’re a great platform for building new cells.
[00:29:30] In some of my talks previously, I’ve talked about the pentose phosphate pathway which fat can’t feed into. You do need glucose for that pathway. We’re going to have debates as to whether or not you have to eat that glucose or whether or not you allow your bodies to make it from the protein that you’re consuming. All in all, for my eight year old, who’s turning nine in a couple of weeks, he’s got a far greater demand on synthesizing brand new cells so he can grow.
[00:30:00] I’m just not comfortable with the evidence that we’ve got that he could be severely carbohydrate-restricted and still grow well, so we allow him to do carbohydrates. What we’re doing is we try and make it the best source of carbohydrates. We’re not getting in lots of refined sugars and carbohydrates and such is my view. Anyway, for him, what we’re looking at … For a young athlete, for a young child who’s trying to develop, what we’re trying to do from a dietary perspective is instill the right philosophy about how you should approach food.
[00:30:30] It’s not a resource that should be gorged on or taken freely. It’s something that should be considered about whether or not you actually should be eating something or how much you should be eating, learning those rules of self-restraint, that just because there might be a lot of junk around that you can access, do you really need to or want it? In that respect then, you’d probably say he’s a lower carbohydrate eater than some of his peers.
[00:31:00] Hopefully, what we’re doing there is by the time he reaches his teenage years, he’s not carrying a lot of excess weight. He’s developed a way that he’s DNA would like him to, he’s developed a good amount of muscle mass, he’s not carrying too much excess body fat. In that respect then, he’s strong enough and fit enough to make a decision as to what type of work or activities he wants to do.Stu
[00:31:30] Got it, that’s good. I haven’t heard or I haven’t heard for a while at least the cellular debate, whereas when we get older, we have no need but we’re not growing these new cells like we are when we were young, so our fuel source doesn’t need to be quite specific. Interesting.Guy
On top of that, Kieron, if you yourself were like a 25 to 30 year old athlete, maybe endurance athlete, which approach would you take? Would you go down the fat adaption process, Steven Phinney and Jeff Volek talk about or …?Dr. Kieron
[00:32:00] Look, personally, I love to run and I had a concussion in June and I wasn’t able to run for about three months until all of the symptoms had recovered. I went for my [inaudible 00:32:01] run in three months about three weeks ago and it killed me, but I absolutely love it. When I look at the datasets, if we had the evidence we do today, if we had that 20 odd years ago … Yeah, we had to do Phinney’s papers from the 80s but 20 years ago, they were only 10 years old.
[00:32:30] It often takes a research paper 20 or 30 years before too many people pay too much attention to it. If we had the datasets that we’ve got coming out now and I was a keen runner, endurance athlete, I would definitely be experimenting and attempting the low carbohydrate, ketosis approach for it. Because look, for some people it seems to work and the arguments that people are having at the moment is whether or not it impacts performance.Guy
There’s only-Dr. Kieron
[00:33:00] If you subscribe to central fatigue mechanisms, then you know that a lot of performance is driven mentally rather than metabolically in some instances. All you want to do is get yourself to a point where you’re in the race and then you can see how it goes. I’d have had 20 years to develop proper race strategies and that’s where we are at the moment. We’ve got a lot of stories coming out, a little bit of evidence coming out in the literature of a very low carbohydrate strategy that can work for endurance athletes.
[00:33:30] What we need to fine-tune still is what the appropriate strategies might be during that event to ensure that you hit that high performance level.Guy
Because there’s also an argument about the fact that the dietary foods that you eat, whether it be more low carb, high fat as a elite athlete compared to the other way around about affecting longevity as well, I don’t know if you’ve heard anything talked about that but …Dr. Kieron
Do you mean longevity in-Guy
In your health.Dr. Kieron
Longevity in life.Guy
Yeah, absolutely but-Dr. Kieron
Because I haven’t read too much down the, how do we say, the recovery side of things. You see the odd reports from time to time about people commenting that they were able to bounce back from training sessions quicker or they might have been able to recover sooner. I don’t know if that real evidence has been properly [crosstalk 00:34:23].Guy
Fair enough.Dr. Kieron
Yeah?Guy
Absolutely. Now, the other topic I wanted to raise, Kieron, while we’ve still got a bit of time left on the podcast, was the conversation we had in Sydney last time we caught up, which was a while back. That was about maximizing muscle recovery and recovery at the time after exercise. You raised some fascinating points and that really got me thinking. Can you just share a little bit of your thoughts behind that? Because I know you haven’t explored it fully but ultimately, it was still definitely worth, I think, raising for the podcast today anyway.Dr. Kieron
[00:35:30]
Sure. From a fuel utilization perspective, what you do in recovery becomes a really fascinating area because what we tend to find is that there’s a couple of different post-workout philosophies that people like to subscribe to. It all depends upon what it is that you’re aiming. You have some people that talk about how do you maximize fat burn in recovery so you can get the most for weight loss or weight maintenance? You have other people who talk about well, the focus in recovery has to be replenishing the stored carbohydrates that you just burnt, so mostly talking about glycogen content.
[00:36:00] Then you’ll have others who like to focus on the protein requirements to make sure that you’re recovering your muscles, so that they’re building and getting stronger and fitter in the best possible way. One of the challenges we have then though is some of the strategies you have for, say, targeting fat oxidation or targeting glycogen replenishment or targeting hypotrophy in protein, interfere with each other.
The challenge that you’ve got is you need to be able to articulate what it is that you’re trying to get from your workout session to properly determine what it is that you want to do in your post-exercise recovery. A lot of the time, you might find yourself talking to somebody who’s exercising and their main aim for exercising is fat loss, and they want to maximize the amount of fat that they’re going to burn from that session.
[00:36:30] Then in the immediate minutes in their recovery, they’re throwing down a sports drink or they’re eating some pasta because they’ve read somewhere that the ultimate replenishment tool is eating carbs to restore your muscle glycogen. Well, the minute you put those carbs into the system, you’re getting an insulin spike, you’re going to interfere with the natural recovery processes that you might have.
[00:37:00] When we’re tracking fat oxidation in recovery, if you’ve eaten within that first hour, it plummets. You’ve effectively switched off any major fat burning capacity from that immediate acute bout. Now, some people have shown and reported that the amount of fat you burn on an exercise, acute exercise bout has no impact on your 24 hour fat oxidation. That could be driven by the fact that these individuals are eating immediately after that exercise bout or very much closer to it instead of impacting that.
[00:37:30] The other thing then is if your focus though is, “Well, I want to recover quickly and I want to recover my carbohydrates so I can do another bout sooner,” then that’s where the carbohydrate groups come in. Because they’re like, “Well, performance is going to be limited by how much glycogen you’ve got in your muscle, so to, to quickly recover that, I need to eat lots of carbs, I need to get it back up.”
[00:38:00] There’s good evidence out there to show that the glycogen replenishment is what we called bi-phasic, there’s two phases. In the immediate window from exercise, there’s a non-insulin dependent pathway. That is, you’ve stopped exercise, you’ve got a whole heap of exercise-induced byproducts floating around and there’s an initial period of glycogen replenishment for a good hour, maybe two hours, maybe even four hours depending upon how much work you did and your general system where that glycogen is replenishing without the need for any other [extortionist 00:38:18] sources of carbohydrates.
[00:38:30] After a couple of hours though, you do need to help the insulin-dependent phase. If you wanted to focus on replenishing your glycogen, that’s when you would be putting it in. Some people argue that … So sorry, I should say so then the glycogen replenishment period is a 24 hour window. Not necessarily trying to get it in all as quickly and possibly can in that immediate window.Guy
Got you.Dr. Kieron
[00:39:00] Then the protein side of things, when you’re focusing on maximizing protein synthesis and muscle growth in recovery, people will tell you that insulin is vital for it, but there’s also evidence that suggests insulin is not necessary for it. It’s actually more driven by the amino acids you have in your system at the time and your protein intake. You can get good muscle resynthesis or regeneration by focusing on your amino acid intake independent of carbs and independent of insulin.
It’s a real messy area at the moment, but you’ve got to be careful to think about what is it that you’re hoping to get from your individual, acute workout session. The other issue we need to be concerned about is whether or not research studies are only ever focusing on one bout.Guy
True.Dr. Kieron
We might do for a research study, we might get somebody in for a series of bouts over a couple of weeks, or depending upon your funding, you might just do one single bout of exercise. How that relates to an ongoing, weekly, monthly cycle is something that we still really need to articulate very clearly. Look, the question is to ask yourself what it is that you’re after in your fat adaptation.

Guy
I don’t know if you got the answer to this one. If you produce an insulin spike after weight training by the food you eat, could that then interfere with the fat or muscle re-growth as opposed to … Because I do wonder that you might recover faster from it but not necessarily better.Dr. Kieron
[00:40:30] Look, I guess it depends upon what your outcome for what you measure better is in that instance. My feeling is that having an insulin spike, if you’re not concerned about what’s happening with your fat oxidation and fat storage perspectives, an insulin spike is not likely to impede your muscle growth but it might not necessarily be necessary to enhance it. Again, it depends upon the paper that you look at, how they’ve dosed people with carbs or how they’ve given them the insulin and what amino acids they’ve got in the system.
[00:41:00] I’d be inclined to think that it’s not going to impede it but then again, yeah, the issue is what you think is better.Guy
Cool.Stu
Fascinating stuff. It’s the science, all right, isn’t it? When you realize, you dig down that deep, there is a-

Guy
It’s fascinating. I obviously worked at a fitness center at the union myself for a long time, and the conversations that would go round there about which way is the best, or you needed it this way or that way.Stu
[00:41:30] Then you’d throw another curve ball in which would be our, I guess, genetic inheritance as well, so the fact that we are different machines.Dr. Kieron
[00:42:00] There’s definitely evidence out there to suggest that your capacity to respond or not respond to a training program may be driven by genetics. There’s also a good argument come out recently that suggests that we’ve oversold how much genetics might play in that. The other thing is that you could quite arguably find good evidence to say that the primary driver for adaptation is the strain that you put on the muscle, the intensity that you work out and then everything else may be secondary.
[00:42:30] The accumulation of byproducts; what you do in recovery. What you’re concerned about in post-exercise nutrition is whether or not what you’re doing is impeding the one-percenter, as some people refer to it, or maybe even the five-percenter. For the most part, if you’re looking for what’s going to be driving my adaptive response, it’s going to be the strain that you put yourself under during that bout.
You prioritize that and then have a think about well, what it is that you’re doing in recovery that might be influencing your capacity to improve?Guy
From my experience mate, everyone’s perception of intensity is very different.Dr. Kieron
[00:43:00] Sure. Well, you get a Borg Scale, a rating of perceived exertion. If you’re not hitting 15 or 16 on that, you know you’re not working hard enough. That’s the easiest one that you can do. Google Borg Scale for RPE, take that along to you. Even if the battery and display breaks on the bike or the treadmill isn’t giving you a good feedback, just go by that. If you’re finding it hard to very hard, you’re doing well.Guy
Perfect, hard to very hard.Stu
Perfect, love it.Guy
Mate, I’m fully aware of the time, Kieron, as well and the podcast is flying and I know you’ve got to shoot soon. We’ll do a wrap up question mate, and what are your non-negotiables to be the best version of yourself?Dr. Kieron
Do you know what? I knew you were going to ask this and I’ve been stewing over it, because I know I’m not the best person I can be at the moment, so I’m thinking, “Maybe I don’t have any non-negotiables and I’ve been negotiating on everything.” Look, to be the best person of myself, for me personally, I exercise fasted.
[00:44:00] I don’t feel I can get the best out of an exercise session if I’ve eaten within a two to four hour window of that session. I like to do everything in a fasted state. The other ones that are independent of exercise is like sleep. Sleep is a massive one, if I’m not getting good sleep.Stu
It is.Dr. Kieron
[00:44:30] There’s quite often times when I know I haven’t gotten everything I wanted to get done in the day, and it might be ten o’clock at night and I’ve just got to go. I’m not staying up for this. I’ve got to go to bed because I know I’m going to be up at half past five or six and that’s going to be more important to me than getting this done. I can always say to people either, “No. I can’t do that,” or I can say, “I can do it but it will take me a week,” and that way I have control over my time. That’s it, I guess time control.Stu
Lovely, [crosstalk 00:44:48] control. Love it.Guy
[00:45:00] Just to bring it back to the study, anyone that wants to participate over the next … Through up until December the 14th and then early January, so they type into Google, Kieron Rooney, University, that would work?Dr. Kieron
Of Sydney.Guy
Of Sydney, of course.Dr. Kieron
That should work. It should pop up. You could even put in Kieron Rooney, sugar and I think I come up on the first page there as my profile page goes.Guy
They could even type Kieron Rooney, 180 Nutrition as well because they’ll come up as well, so-Dr. Kieron
Excellent, and if you guys were able to upload that flyer, that will have the contact details on it as well.Guy
I’ll put that flyer on the-Stu
We’ll do that.Guy
When this podcast goes out mate. I’ll link your email and everything to the show notes and we’ll push it across our channels and we’ll fill out 120. Hopefully, you’ll see me in Lidcombe maybe between now and the end of January doing the test myself.Dr. Kieron
Absolutely, and I expect photos to go up on the website when you are in here, and we’ll see how you pump it out.Guy
Exactly mate. I’ll just put myself in the elite athlete bracket. How does that sound?Stu
Good luck with that Guy. Work him hard Kieron, that’s all I can say.Dr. Kieron
Oh, we will. We will indeed.Guy
I’ve done VO2 max before. It’s not pretty. Beautiful, thanks for your time Kieron. Thanks Stu and-Dr. Kieron
Thank you very much. I really appreciate it and yeah, definitely, if anybody wants to come in, just email us and we can book you in and you get you that free health assessment.Guy
Awesome.Stu
Brilliant.Guy
Cheers guys.Stu
Thank you Kieron. Bye-bye.Dr. Kieron
Thank you very much. See you guys.